HIV mainly infects CD.sub.4 -positive lymphocytes (helper/inducer), gradually reduces the number of the cells and finally causes severe acquired immunodeficiency syndrome (hereinafter referred to as AIDS). Many efforts have heretofore been made in order to treat AIDS, but development of vaccine is extremely difficult so that development of antiviral agents has been expected. Though the anti-viral agents having inhibitory actions on a reverse transcriptase inherently possessed by the virus, which have been approved at present, have life-prolonging effects on AIDS patients, the agents cannot cure them completely. Further, these inhibiting agents have many problems that side effects such as myelopathy and digestive system disorder, etc. are severe, drug-resistant viruses are separated with high frequency from patients to whom the agent is administered for a long period of time, and others, whereby developments of novel chemicals and therapy using multiple agents in combination have been earnestly desired.
Recently, there has been reported the anti-HIV activity of DR-3355 which is an optical isomer of a synthetic antibacterial agent, Ofloxacin, having a quinolinecarboxylic acid skeleton (J. Nozaki, Renard et al., AIDS 4, 1283 (1990)). However, when the present inventors studied the cellular disorder-suppressing activity of DR-3355 to HIV-infected cells according to the method of R. Pauwel et al. described below, no anti-HIV activity was recognized. Also, there have been described the anti-HIV activities of Norfloxacin, Enoxacin, Ciprofloxacin, Lomefloxacin, Difloxacin, Tosufloxacin, etc. (WO 90/13542), but no anti-HIV activity was also recognized regarding these compounds.
The present inventors have studied about the anti-HIV activities of various kinds of quinolinecarboxylic acid derivatives and found that a quinolinecarboxylic acid derivative whose hydrophobicity is strengthened and whose antibacterial activity is weakened by introducing a trifluoromethyl group at 8-position and a cyclic diamine (e.g., a piperazinyl group or homopiperazinyl group which may be substituted) substituted by a phenyl group or an aromatic heterocyclic ring group at 7-position can specifically suppress growth of HIV in HIV-infected cells and further has an activity of suppressing a cytopathic effect (CPE) of HIV, in order to accomplish the present invention.